During the next 5 year grant period we shall focus upon the quantitative control of epidermal and hair root protein synthesis in tissue slice, cell-free and tissue culture systems. The translational control proteins including initiation, elongation and release factors will be identified, isolated and characterized. The endogenous inhibitor of initiation which we have already identified will be characterized, other endogenous inhibitors of translation will be sought and the effects of exogenous inhibitors will be determined. The role of polyamines and polyamine metabolizing enzymes in control of epidermal and hair root protein synthesis will be determined and inhibitors of polyamines will be analyzed with the aim of developing potential therapeutic agents for use in proliferative skin disease. Epidermal and hair root phosphoproteins will be isolated from animals given parenteral 32P, from animal and human tissue slices incubated in vitro and from epidermal tissue culture lines. The effects of promoters and inhibitors of phosphoprotein formation will be determined and the role of protein phosphorylation in control of epidermal protein synthesis will be ascertained.